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Discussion Starter · #1 ·
I have not seen any one attempt a transmission line build on these XBR2 subs, anyone have any thoughts on how well this box type will sound. I really like the sound of infinite baffled subs, it is very clear and non resonant, and the only box that is non-resonant in my experience is a trans-line.I would like to hear anyones input on this idea, Thanx!
 

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Discussion Starter · #4 ·
My project I am conteplating is for my RV, I have a space abt 52"long by 22" tall by 20" deep, so approx 10.8 cu ft. I have read prior (older) articles from Bailey on up through Speakerbuilder magazines from issue 1 to October 2003, some of the ideas suggested only 25% of cone area is needed if extensive damping is used. Only a percentage of the back wave is used, and only at the very lowest frequencys, Ive heard that a T-line is the only enclosure that will actually lower the drivers resonant frequency once it is in the cabinet. I do expect it to be large, I think the Exodus drivers have the best motor and suspension setup to handle low frequency excursions required for this type of cabinet as the driver is unloaded below resonance as per a LLT, but should not have to worry about port chuffing. I have looked at quarterwave site, I will go back for some more research there, just wondered how these Exodus drivers would do.
 

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You are right! you can use 25% (driver SD) port area if the driver is not like my ex sub which has VAS-60L and Mms-360.
Even with 75% of driver SD port area I didn't get rid of the noise. Also it's a good thing to use some damping to achieve the tuning you want, normally you should tune it to the driver Fs .
Anyway it will have one octave down extension below tuning, so it's going very deep and has a tight and accurate bass.
 

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Here is an excel calculator from t-line speakers
You need to enter your driver params in to it

And also i had an email from Martin J. King saying the Drivers with Qts lower than 0.3-0.35 are hard to control in a tl design
 

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Discussion Starter · #7 ·
Thanks for the zip file Velti, I am such an incompetent computer guy I had to have my son install office 1.3, now just need to play with it, also try to wrap my mind around metric vs inch sizes. I appreciate all the learning on this forum.
 

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I've not done any simply because of the size necessary for the subs. I don't see an advantage over a ported or PR build which is much simpler and smaller.



Kevin Haskins
Exodus Audio
 

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I've not done any simply because of the size necessary for the subs. I don't see an advantage over a ported or PR build which is much simpler and smaller.



Kevin Haskins
Exodus Audio

It gets long indeed, but for the LLT fans here it would be even moderate sized :yes:. For example 40Hz tuned T-Line yields this:
343m/s (speed of sound in air envir.) devided by 4 (quater wave length) then devided by 40Hz = 2.14meters or 7.03foot. Actually T-Line builders dont do it so long. Instead they "center" the imedance at freq around 40Hz - 45Hz and the lower half of the freq hump reaches 20-18 Hertz :bigsmile:easily+room gain you got it.

There is a lot more to be considered in terms of driver specs (Qts>=0.35) and even more, but thats the idea.

And T-Line is a non-resonant design, just like the horn but with much smaller cabinets. Here is an example design with a 10 inch and an old shiva 12 inch sub, those here are much smaller than the majority of the LLTs :whistling::


http://www.teresaudio.com/haven/subs/subs.html

and

http://www.t-linespeakers.org/projects/steve/index.html


Disadvantage here is the reduced output level compared to a horn, but whether it is lower than a ported am not sure about that.

That reminds me of the Bose and how well do they sound with small cabinets, with a tube bent inside and with 30$ or less sub-drivers :heehee:.
 
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